First Language Acquisition Test #2: Phonology and Vocabulary Development

Phonological Development

• Birth to 2 years

• Primary focus of the child

• Children must acquire both phonemes and allophones

Phonemes

• Sounds that contrast and cause words to have different meanings

• E.g. pack and back

• Separate or distinct sounds

Allophones

• Phonetic variants of phonemes

• Different ways of pronouncing a sound

• Are predictable and ever occur in the same phonetic environment

• Do not change the meaning

• Belong to a phoneme

• Differ across languages (e.g. English vs Thai)

Phonemes and Allophones relating to Child Language Acquisition

• Children must determine which sounds are phonemes, and what allophones each phoneme has.

• Requires the perception of sounds found in the linguistic environment (kids’ perception is acquired at the age of 1)

• Children must also produce sounds found in the linguistic environment (both phonemes and allophones)

• Production of all of the sounds in a language takes until after age 4 -> Acquisition Order

• Acquisition is gradual -> child phonetic processes

Phonotactics

• Study of syllables

• Children must also combine sounds into syllables and syllables into words -> phonotactics (study of syllables)

• Kids are able to percieve sounds, even if they can’t produce them. E.g. A child who pronounces “fish” as “fiss,” but when the parent imitates the child, the child corrects the parent and recognizes the parent said it incorrectly.

Pre-Linguistic

• Period of development from birth to first words (approximately one year)

• During this time, there is a change in:

  • Children’s perception of sounds

  • Children’s responses to language

  • How children produce the language in their linguistic environment

Perception of Language

• The ability to hear contrasts in native language and non-native languages (specifically, allophones)

• Allows for the acquisition of any language

• Categorical perception

• Innate ability

• Begins before birth (3rd trimester of gestation)

• They can hear intonation/rhythm/melody the most

• Between birth-6 months:

• Children have the ability to hear very small differences between speech sounds (infants only know the allophones, don’t know the phonemes).

How is the perception of language tested?

• High Amplitude Sucking (HAS) - sucking increases when infants hear a new/different sound

• Head turning - infants turn their head in the direction of a new/different sound

6-12 Months Perception of Language

• Gradual decrease in ability to perceive small differences between sounds

• Focus on contrasts found in the linguistic environment (set up categories that match adult language)

• Loss of contrasts that are not found in the linguistic environment

Categorical Perception

Boundaries for categories align with adult categories

Responses to Language

• Infant responses to language gradually change over the pre-linguistic period

• During pre-linguistic period, these responses show how infant perception develops

• A newborn would be startled by loud noises and turns its head toward loud noises. They can also be calmed by the sound of a voice and prefer their mother’s voice.

1-2 Months Response to Language

Smiles when spoken to

3-7 Months Responses to Language

Respond to different intonations

Attitudes Intonations

Can differentiate happy, sad, or angry voices

8-12 Month Responses to Language

• Respond to some words (such as their names and the word “no”)

• Recognize some phrase from routines and games

Production of Language

Pre-verbal Vocalizations that change over the first year

Four Stages:

1. Reflexive Vocalizations

2. Comfort Stage Vocalizations

3. Vocal Play

4. Babbling

Reflexive Vocalizations

• Automatic responses to stimuli (e.g. crying, coughing, burping, etc.). For the first 1-2 months, this is the only possible type of vocalization (they are not linguistically or physically ready).

• Linguistically - they haven’t figured anything out language wise

• Physically - infants need to grow and develop more physically before speech can occur (larynx is too high in the neck, tounges are too large for their mouths, little separation between oral and nasal cavities)

Comfort Stage Vocalizations

• Indicate comfort (such as smiling starting at 1-8 weeks or laughing at around 16 weeks.

• Beginning of something not reflexive (non-reflexive) because they can choose whether to do it or not

Vocal Play

• 4-6 Months

• Children produce a combination of liguistic and non-linguistic sounds

• Non-linguistic Sounds - shrieks, growls, squeaks, blowing raspberries

• Linguistic Sounds - initially back sounds such as [k] and [g], later front sounds such as [p], [b], and [m].

• Range of loudness: very loud -> very soft

• Range of pitch - very high -> very low

• Child is ‘playing’ determining what sounds can be made with the vocal tract

Babbling

• first sequence of sounds

• CV (consonant followed by a vowel) sequences that have no meaning

• Reduplicated, variegated, jargon

• Babbling is universal, accross all children (doesn’t matter if child is deaf)

• Same sounds [p, b, t, d, k, g, m, n, w, h]

Reduplicated Babbling

• 6-8 months

• Strings of the same CV sequence (e.g. “bababababa”)

Variegated Babbling

• 8-10 months

• Not all kids do this, strings of different CV sequences with some variation (e.g. “mamapadama”)

Jargon

• 10-12 months

• Strings of different CV sequences with adult-like intonation, but no meaning. Sounds like they are speaking the adult language (e.g. rising vs falling intonation)

• It coexists with real speech

Protowords

• (PCF - Phonetically Consistent Form) - words that children produce

• Not babbling

• Have meaning

• Different from the actual adult word, but have the same meaning as the adult word.

• E.g. Kugi -> book

           Bupa -> blanket

           Baba -> milk

• Phonetic forms with a consistent form and consistent meaning

• indicate that the child has linked sounds with meaning

• Transition to real words

• Protowords are not universal and usually disappear quickly

  

Acquisition Order

• For all children, speech gradually develops out of babbling.

• Speech and babbling co-exist for a time

• Universality - For all children, sounds found in babbling are among the earliest acquired and those first used in words.

• The acquisition order is fairly consistent across languages

• Stops -> fricatives -> affricates

• Voiceless fricatives/affricates -> voiced fricatives/affricates

• Kids get both voiceless and voiced stops at the same time.

• Liquids and interdentals are a late acquisition

• Kids tend to acqiure less marked sounds (less common) first, and then marked sounds (more common) later.

• Acquire sounds (vowels and consonants in a particular order) - universal (mostly)

Vowel Acquisition Order

• Vowels acquired before consonants

• The vowels [i], [u], [o], [a] are aquired first

Consonants

- [b], [d], [m], [n] are first acquired at the beginning of words

- [p], [t], [k], [n] are acquired at the end of words

Manner of Articulation (stops, nasals, fricatives, affricates, glides)

• Obstruents

• Stops acquired first, followed by fricatives and affricates

• Sonorants (nasals, liqiuds, glides) - nasals are acquired first, liquids are the last manner to be acquired

Place of Articulation

• Earliest - bilabial and alveolar (front consonants) - easier to articulate, you have more control.

• Last place of articulation are interdentals.

Age 2 Inventory

Front sounds:

• [p, b, m, f, w] (labial)

• [t, d, n, s] (alveolar)

Back sounds:

• [k, g] (velar)

• [h] (glottal)

Age 4 Inventory

Total Inventory:

[p, b, m, f, v, w] (labial)

[t, d, n, s, z, l, r] (alveolar)

[ʃ, tʃ] (alveopalatal)

[j] (palatal)

[k, g, n] (velar)

[ʔ, h] (glottal)

Added from previous inventory:

[v, z, l, r, ʃ, tʃ, j, ʔ]

After Age 4 Inventory

• Interdentals [θ, ð]

• Voiced alveopalatal fricative, voiced alveopalatal affricate [ʒ, dʒ]

Inventory Variations

• This is the case for the majority of kids, but not all (these are the norms)

• Variation across languages

• Variation between children acquiring the same L1

• Variation within a child

• Some examples of the different types of variation between and within children:

• Individual preferences (they like certain sounds)

• Different pronunciations of the same sound depending on the complexity of the word.

• Position of the sound in the word

• How recently the word was acquired

• Can result in homonyms (words that have the same pronunciation, but different meanings)

• Frozen forms - early pronunciation that continue even though the child is capable of more complex pronunciations.

Vocabulary Development

• Acquisition of words

• Begins at birth and continues throughout development

• Comprehension begins around 7-8 months

• Production begins around 12 months

• When kids first start to acquire words, it begins very slowly. The first 50 words take a long time to acquire (around 18 months)

• Speeds up - word spurt (vocabulary, words they can comprehend/produce speeds up rapidly)

• 60 000 words by high school

Child Strategies

1. Conservative

2. Risk Taking

Conservative Children

• Take a word-by-word basis

• Learn one word after another

Risk Taker Children

• Global Strategy

• Attempting to say entire words/phrases/sentences early on

5 Acquisition Tasks

1. Segment the speech stream

2. Build up mental lexicon

3. Assign meaning to words

4. Assign meaning of lexical categorie

5. Assign argument structure to words

Segment the Speech Stream

• Pre-linguistic development

• Birth to 1st birthday

Build up mental lexicon

• early words

• Vocabulary development

• Categorizing words and storing them (this is the reason the first 50 words are acquired so slowly is because the child hasn’t formed an organization system yet)

Assign meaning to words

• nouns and verbs

• Strategies and errors

Assign words to lexical categories

Part of morphology and syntactic development

Assign argument structure to words

Part of syntactic development (e.g. throw, threw)

Speech Segmentation

• Dividing the speech stream into words

• During pre-linguistic development

• Birth to first words (approx. 12 months)

• E.g. theredonateakettleoftenchips

    The red on a tea kettle often chips

OR There, Don ate a kettle of ten chips

Probabilistic Theory

• Children listen to the speech stream and make guesses about what a word is (called inferences)

• Tend to use inductive reasoning

• Make use of probability

• Statistical learning (part of broad language faculty)

• Based on transitional probability (I see this, which is followed by this, therefore, if I hear this, it will be followed by this)

• Infant research - lots of evidence to show that infants use probability, repsond to new sounds, and have preferences for sounds

Deductive Reasoning

If A is bigger than B, if B is bigger than C, then A is bigger than C

Inductive Reasoning

• All the tigers I have seen have orange fur and black stripes, the next tiger I will see will most likely have orange fur and black stripes

• But this is not certain since it could be a tiger with white fur and black stripes

Statistical Learning Strategies

• Probabilistic cues

• Prosodic cues

• Other

Probabilistic Cues

• Vowel harmony - all vowels in a word are the same kind (e.g. seen in Turkish)

• Vowels of the same kind are more likely to be in the same word (kids use this to divide the speech stream)

• Note: consonant harmony is unique to child language, and not seen in any actual language

Example:

[gire]                vs                [giru]

Same word                      Different words

• Sequences of Sounds - can be used to indicate word boundaries or a sequence of sounds within a word.

E.g. [ŋk] More likely to indicate a word boundary (e.g. wrong time)

[nk] More likely to occur within a word (e.g. tinker)

Prosodic Cues

• Use the prosody of the language

• Refers to the stress, tone, and intonation patterns of a language

• Use the prosody of the language

• Stress - highlights portions of the speech stream

• Vowels that are stressed are the most prominent (louder, longer, higher in pitch)

Two ways in which children use stress to segment the speech stream

1. Stress placement (globally)

2. Stress patterns (beginnings and endings of words)

Stress Placement

• Content words are stressed (nouns, verbs, adjectives, adverbs)

• Function words are unstressed (the, a, prepositions)

E.g. The bird might land on the fence

               N                V                 N

• Spotlight that directs children to the nouns and verbs in the speech stream.

Stress Patterns

Provide information on the beginning or ends of words

Types of Stress Patterns

1. Trochaic

2. Iambic

Trochaic

a stressed (strong) syllable followed by an unstressed (weak) syllable -> beginning of the word

E.g. water, doctor, baby, candle

Iambic

an unstressed (weak) syllable followed by a stressed (strong) syllable

E.g. giraffe, guitar, advice, explore

Trochaic vs Iambic

• In English, the trochaic pattern is more common. There is is a strong probability that the stressed syllable is the beginning of the word

• The reason kids say “nana” for the word “banana” is because they prefer the trochaic pattern, and emphasize the stressed syllable of the word.

• Infants prefer the trochaic pattern over the iambic pattern

• Trochaic pattern results in unstressed syllable deletion

Other Cues

• Utterance Edge

• Matching cues

Utterance

stretch of spoken language preceded by and followed by a period of silence (e.g. phrase, sentence, conversation)

Salience

• Some positions in an utterance are more salient than others (direct the child’s attention, like a spotlight; e.g. stress)

• Words at the beginning and the end of an utterance are the most salient

- E.g. Bring me that toy!

           V                    N

- (You) bring that toy to me! (harder to understand)

​            V              N

Matching Cues

• Based on known words; the use of words that the child knows to find new words

• Kids will check a sequence for known words and segment (take out) the known portion

• Then they assume that whatever is left over is also a word.

• E.g. “cutedoggie”

  • The child knows the word “doggie,” so they can segment this word off and assume “cute” is a new word.

• E.g. “prettycutedoggie”

  • The child knows the word “doggie,” so that leaves “prettycute.” The child will assume this is one word, so more segmentation is needed.

• Eg. “prettybaby”

  • The child knows the word “baby.” That leaves “pretty.” They figure out that “pretty” is its own word, leaves “cute.”

Segmentation Errors

• Children will not always find the correct start or the correct end of adult words.

• Linked to probability - cues will most likely find words, but it is not guaranteed that what is found will be a word.

Types of Segmentation Errors

1. Undersegmentation

2. Over segmentation

3. Missegmentation

Undersegmentation

• Two or more adult words are one word to the child (e.g. “prettycute”)

• The result of insufficient sugmentation

• This is known as an unanalyzed chunk

• E.g. “Idunno” (I don’t know)

• “lmno”

• “Wannago” (Want to go)

Oversegmentation

• One adult word is two (or more) words to the child.

• Result of too much segmentation

• Based on comparison with other words in the language

• E.g. “be good” -> segmented into two separate words

• “Behave” -> two words to the child (“be have”)

Missegmentation

• Analysis of a sequence of two or more words into different words

• Often based on similar pronunciation

• E.g. “Pulitzer Prize” -> “pull it surprise”

Two Types of Segmenting Approaches

1. Analytic

2. Gestalt

Analytic

• Children who divide the speech stream into the smallest speech units possible.

• Tend to have short, clearly articulated utterances from beginning of production.

• Not many segmentation errors

• Oversegmentation is more likely than undersegmentation

• Tend to be conservative with a word-by-word approach to acquisition

Gestalt

• Children who do not divide the speech stream into the smallest possible units

• Tend to produce large utterances that are often poorly articulated

• More likely to make segmentation errors

• Undersegmentation is more likely than oversegmentation

• Tend to be risk-takers

• Global approach to acquisition, rather than word-by-word

Early Words

• Children start producing words at approximately 12 months

• From approximately 12-18 months, children acquire words very slowly

• Tend to have the following characteristics:

Pronunciation                    Situational

Categories                         Sound effects

Context                              Cognitive development

Cognitive Development

• Object permanence

• Means-end

Object permanence

The idea that an object continues to exist, even when it can’t be seen (e.g. if the child can use words like “bye-bye” or “more,” it shows that they have object permanence)

Means-end

A sequence of steps to achieve a goal (e.g. “tada” or “uh-oh”)

Leaning Nouns

• Sometime after 18 months, some children go through a word-spurt and acquire words rapidly

• Children must connect words with meaning and are fast mappers

• Fast mappers - don’t need to hear a word a lot to map it onto its meaning

• Children have a bias for nouns - this is because nouns are found in all languages and work the same way (verbs do not work the same way in all languages), therefore, it will make up the majority of their vocabulary.

• Children acquire object nouns first -> concrete nouns: objects you can see, touch, feel, and interact with

In-born Strategies

Most likely part of the narrow language faculty acquisition device to allow for fast mapping (these are cognitive strategies)

Types of In-born Strategies

1. Whole Object Assumption

2. Type Assumption

3. Basic Level Assumption

4. Mutual Exclusivity

Whole Object Assumption

Words refer to the entire object, not one of its properties (e.g. sheep → entire sheep)

Type Assumption

words refer to a type of object and not just an individual object (e.g. “sheep” doesn’t refer to one specific sheep, but anything that has the same characteristics. Sheep → type of animal)

Basic Level Assumption

words refer to objects that are alike in basic ways (e.g. sheep → only animals that share the same characteristics)

Mutual Exclusivity

the assumption that an object can only have one name; new words refer to objects that do not have a name (e.g. a dog cannot be a hound). Can be used to override the whole object assumption (Starts with the big picture, and breaks it down further. E.g. the word “horn” must refer to something on the goat).

Overextension

• Too many items within a category (e.g. all women = mommy)

• One word for all objects that share similar characteristics (e.g. women with a baby = mommy)

• Based on perceptual similarities between objects (e.g. a ball and the moon are both round; “ball in the sky,” “cow/horse”)

• Occurs to fill a lexical gap since children don’t have all words yet. This also occurs due to a lexical retrieval failure. Kids have an immature category system (as adults, we have words organized into categories in our mental lexicon)

Underextension

• Children include too few items within a category

• E.g. cat = family cat

• Based on their own personal experiences (if the child has a cat at home, that is the only cat that they consider a “cat”)

• E.g. gardening = planting flowers

• Linked to the child’s developing lexical processing abilities; still figuring out how to categorize things

Note: overextension is more common than underextension

Learning Verbs

• Harder than nouns

• Possible reasons for this:,

  • Verbs refer to actions (active verbs)

  • Harder to find in the child’s linguistic environment

  • The beginning and the end of an action is not always obvious

  • Do not remain the same, but change as they happen (e.g. rolling something starts of close and gets further away)

  • Distribution - harder to find within a sentence and not as predictable from the linguistic context as are nouns

  • Universality - found in all languages, but properties may be different

    • E.g. verbs of motion - manner of motion (how the motion happens) and path of motion (where the motion is going)

    • English verbs of motion encode manner but not path

    • E.g. “The bottle floated into the cave.”

Manner of Path of motion

Motion (verb) (Preposition)

       - E.g. “La botello entro en la cueva flotendo.”

Path of motion (verb). Manner of motion (adverb)

Syntactic Bootstrapping

• Using clues from sentence structure

• E.g. “Mom zwigs we should have soup.” → zwig = to think

Verb Errors

• Promise vs forgot (Children find it difficult to perceive time. They also think that if you break your promise, you forgot. Children equate the two)

• Pour vs fill (Children have a hard time distinguishing the difference)

• Surprise (Children have a hard time understanding the meaning of this word - can’t take the perspective of others)

Sources Variation of Verb Acquisition

• Cultural differences

• Individual differences

Note: these have no long term effect on vocabulary development

Cultural Differences

• Nouns - not all languages use determiners

• Verbs - (like discussed previously) don’t work exactly the same way across languages

• Languages are different

• Not all children will develop their vocabulary in the same way

• E.g. Children acquiring English acquire more nouns than verbs

• E.g. Children acquiring Mandarin acquire more verbs than nouns

Individual Differences

• Phonological acquisition and nouns (as discussed previously)

• Referential vs expressive children

Referential Children

• Focus on labelling objects

• Acquire more nouns

Expressive Children

• Focus on social aspects

• Acquire less nouns

Factors that can have an Effect on Verb Acquisition

• Linguistic Environment

  • Amount of labelling done for child (more likely to be referential)

  • Around of social interaction (more likely to be expressive)

  • Vocabulary used

• Education level of parents

• Birth order of the child (more likely to be referential)

• Child’s phonological memory and phonological awareness. Some children are able to remember sounds a lot better than others. These children are more likely to be referential.